1. Field of the Invention
The present invention relates to a wireless communication system, and, more particularly, to a method and apparatus for transmitting a signal in device-to-device communication.
2. Discussion of the Related Art
In cellular communication, a user equipment (UE) existing in a cell accesses a base station in order to perform communication, receives control information for exchanging data from the base station, and transmits and receives data from and to the base station. That is, since the UE transmits and receives data via the base station, the UE transmits data thereof to the base station in order to transmit the data to another cellular UE and the base station, which has received the data, transmits the received data to another UE. Since one UE should transmit data to another UE via a base station, the base station performs channel and resource scheduling for data transmission and reception and transmits channel and resource scheduling information to each UE. When communication between UEs is performed via a base station, channel and resource assignment for data transmission and reception between each UE and the base station is necessary. However, in device-to-device communication, a UE has a structure for directly transmitting and receiving a signal to and from another UE without intervention of a base station or a relay.
Since device-to-device communication of a UE is performed in parallel with communication between a UE and a base station, collision there between may occur. There is a need for a method for preventing or dealing with such collision.